A truly excellent wartime espionage film. Terence Stevenson (Robert Donat) is a bomb disposal officer dealing with unexploded bombs during the Blitz. As if that isn't dangerous enough he is chosen to head to Eastern Europe to infiltrate a German factory in Czechoslovakia which is producing a new deadly chemical weapon. Unfortunately for Terence, who uses the cover name Jan Tartu, his contacts are captured by the Gestapo before he can make contact.
He takes board at a house but quickly discovers that there is more than meets the eye to Maruschuka (Valerie Hobson) and Paula (Glynis Johns) who he both suspects are involved somehow with the underground. However, Maruschuka thinks Terence/Jan is a Gestapo agent and tries to get the German officer sweet on her (Walter Rilla) to kill him! Luckily she discovers that Terance/Jan is the real deal just in time but as the Germans are getting ready to produce the first shipment of gas can a successful sabotage mission be staged?
The film travels at a fast pace and leaves little room for much subtly but has an exciting plot with plenty of twists and turns. Although the film has unmistakable propaganda touches, it also has room for a great deal of shade. Is Maruschuka a collaborator or an agent herself? Does Terence really know what he is doing? The chemical factory sets are very impressive and wartime footage is cleverly interwoven into the film.
